1. Field of the Invention
The present invention relates to a transfer device for handling film-shaped works. More specifically, the present invention is directed to a transfer device that feeds a film-shaped work from a supply section to a winding section through a process stage.
2. Description of the Related Art
Generally, as handy electronic devices including portable phones and mobile devices are becoming compact, their electric circuit boards are shrinking. Accordingly, current material sources (or works) for circuit boards tend to shift from a thick hard type to a thin tape-shaped type.
A typical tape-shaped work had a thickness of about 0.1 mm a few years ago, but it is now about 0.06 mm thick. Furthermore, works having a thickness of 0.05 mm or less and a width of 100 mm to 250 mm are highly in demand.
When an electronic circuit board is formed from such a tape-shaped work, the work may be loosened and its side edges may be warped while the work is being fed by a transfer device. In order to overcome this disadvantage, a mechanism of JP2836787 has been known. This mechanism is equipped with a lateral transfer device for allowing a work to be handled stably.
This lateral transfer device is built in an exposure device, and is configured to feed a tape-shaped work for each block laterally in order for the device to transfer patterns on a mask to the surface of the work during an exposure process.
However, if a work is fed laterally, it is likely to be loosened due to its weight. In order to prevent this, a holding mechanism of JP2836787 has been conceived. This holding mechanism has pairs of rollers for pinching a work so as to adjust a tension of the work.
On the other hand, a general transfer device has a curved transfer route and, therefore needs to prevent excess loads from being applied to a work at curved portions. JP2836787 discloses a transfer device equipped with an air dancer for adjusting a tension of a work. With this air dancer, the work can be fed to an exposure stage and fixed there, while the work does not undergo any extra tension.
A typical exposure device (for example, one disclosed by JP2836787) employs a lateral transfer system by which a work is fed laterally, and it is exposed to light in a horizontal position. However, JP-A2005-326550 and JP-A2005-91903 and JP-A2798158 disclose a vertical transfer system for feeding a work vertically in order to increase the patterning resolution by preventing contaminants in the air from being adhered to the surface of the work and/or a mask.
The mechanism of JP-A2005-326550, JP-A2005-91903 or JP2798158 uses rollers for supplying a work to an exposure stage.
In addition, a turning device that curves a feeding route of a work in order to feed the work to a process stage appropriately has been known. An example of such a turning device is disclosed by JP2788207. This turning device floats a work by means of air blown from a jet tip formed on a thin plate on a surface of a fixed shaft, and feeds it at corners.
Typically, a protective sheet having the same size as that of a work is put on a tape, and they are wound around a reel together. This sheet is aimed at preventing contaminants from being adhered to the surface of the work, or leads of electric components mounted on the work from being bent or damaged.
However, the protective sheet is unnecessary during an exposure process. Accordingly, a typical transfer device removes a protective sheet from a work while it is being fed from a supply reel, and feeds only the tape to a process stage. Subsequently, another protective sheet is put on the processed work, while the work is being wound around a take-up reel.
FIG. 13 schematically shows a transfer device as disclosed by JP3663421, JP-A2004-193259 or JP-A2005-93958.
Referring to this drawing, a transfer device 1100 includes:
1) a supply reel 1101 around which both a tape T1 and a protective sheet S1 are wound;
2) a take-up reel 1102 that winds the tape T1 fed from the supply reel 1101;
3) another take-up reel 1103 that winds the protective sheet S1 fed from the supply reel 1101;
4) another supply reel 1104 around which a protective sheet S2 that is to be put on the tape T1 is wound; and
5) a process section 105 positioned between the supply reel 1101 and the take-up reel 1102. Only the tape T1 is subjected to a process at the process section 105, because the protective sheet S1 is fed separately and away from the tape T.
The transfer device 1100 is configured to adjust the tension of the protective sheet S1, while the protective sheet S1 is being wound around the take-up reel 1103.
Specifically, (1) JP3663421 discloses the nip rollers between the supply reel 1101 and the take-up reel 1103.
(2) JP-A2004-193259 discloses a motor coupled to a driving shaft of the take-up reel 1103 through a clutch.
(3) JP-A2005-93958 discloses a spring for applying an elastic force to the protective sheet S2.
FIG. 14 schematically shows another transfer device as disclosed by JP-A2005-5586.
Referring to this drawing, a transfer device 1200 includes:
a supply reel 1201 around which both a tape T1 and a protective sheet S1 are wound;
a take-up reel 1202 that winds the tape T1 and the protective sheet S1 which are both fed from the supply reel 1201;
a transfer system 1203 that feeds the tape T1 from the supply reel 1201 to the take-up reel 1202;
a transfer system 1204 that feeds the protective sheet S1 from the supply reel 1201 to the take-up reel 1202; and
an inspection device 1205 provided in the transfer system 1203.
In this device 1200, both the tape T1 and the protective sheet S1 are fed from the supply reel 1201, and they are forwarded by the transfer systems 1203 and 1204, respectively. In addition, only the tape T1 is subjected to a test by the inspection device 1205.
However, the above-described transfer devices have the following disadvantages.
The transfer device of JP2836787 discloses the air dancer for preventing a work fed from the supply reel from being loosened due to its weight and from undergoing excess tensions.
However, in a transfer device of this type, a work is kept in a horizontal position on an exposure stage, and the work is brought into contact with the mask. Therefore, as becoming wider, the work is more likely to be loosened. Thus, it is difficult for the transfer device to prevent the looseness of a wide work.
Furthermore, the mask and the work are brought into contact with each other or are placed close to one another. Hence, contaminations may be adhered to the surfaces of the mask and the work because of static electricity. This may cause the deterioration of the patterning resolution.
The transfer device of JP-A2005-326550, JP-A2005-91903 or JP2798158 discloses the pairs of rollers for pinching a work before and after the exposure stage. With this device, the mask, optical system and work are aligned easily, but the work is prone to undergo excess loads from the rollers.
Moreover, the transfer device as shown in FIG. 13 needs the take-up reel 1103 dedicated for winding the protective sheet S1 fed from the supply reel 1101. In addition, the nip roller, clutch and spring for adjusting the tension of the protective sheet S1 on the take-up reel 1103 are also required. Thus, this transfer device must be equipped with many accessory members. Moreover, the supply reel 1104 is installed near the take-up reel 1102. This installing process can be troublesome.
In the transfer device as shown in FIG. 14, the protective sheet S1 fed from the supply reel 1201 is directly wound by the take-up reel 1202. Therefore, any accessory members are unnecessary. However, the supply reel 1201, inspection device 1205 and take-up reel 1202 are arranged laterally. This arrangement leads to the enlargement of the device. Accordingly, a large area must be ensured for installing such an enlarged device.
Furthermore, in the transfer device 1200 as shown in FIG. 14, the transfer system 1204 is positioned above the inspection device 1205. In this structure, contaminants on the protective sheet S1 may fall down to the working area of the inspection device 1205.
Moreover, the transfer device 1200 discloses the transfer systems 1203 and 1204. The system 1203 loosens the tape T1 between the supply reel 1201 and the inspection device 1205 and between the inspection device 1205 and the take-up reel 2002 in order to adjust the tension of the tape T1. Meanwhile, the transfer system 1204 adjusts the tension of protective sheet S1 near the take-up reel 1202. Since both tension-adjusting methods are quite different, it is difficult for the device 1200 to run the tape T1 and the protective sheet S1 in sync with each other. As a result, the take-up reel 1202 may fail to wind them in balance.
Taking the above disadvantages into account, the present invention has been conceived. An object of the present invention is to provide a transfer device that can feed a work in a stable condition without applying it any excess loads. An additional object of the present invention is to present a transfer device capable of winding a work and a protective sheet in balance.